Global Patent Index - EP 0999531 A1

EP 0999531 A1 20000510 - An article surveillance system

Title (en)

An article surveillance system

Title (de)

Artikelüberwachungssystem

Title (fr)

Système de surveillance d'articles

Publication

EP 0999531 A1 (EN)

Application

EP 00100804 A

Priority

  • EP 97904707 A
  • SE 9600528 A
  • SE 9601033 A

Abstract (en)

An article surveillance system for detecting the presence of articles in a detection zone (18) has at least one transmitter means (11, 13) and at least one receiver means (12, 15) for transmitting and receiving, respectively, electromagnetic radio-frequent signals in the detection zone or in a proximity thereof. Each article is provided with a sensor or marker (20) operating as a transponder for transmitting an electromagnetic radio-frequent reply signal to the receiver means when receiving a signal from the transmitter means. Furthermore, the system has a coil arrangement (16) with driving means (17) for generating a low-frequent magnetic modulating field in the detection zone (18), and a controller (14) operatively connected to the transmitter means (11, 13), the receiver means (12, 15) and the coil arrangement (16, 17). Each sensor (20) is arranged to transmit a reply signal, the amplitude of which is modulated by the magnetic modulating field, and the receiver means is arranged to receive and to demodulate the amplitude-modulated reply signal. The controller (14) is arranged to supply modulating signals (imod) to the coil arrangement (16, 17), to receive the demodulated signals (idemod) from the receiver means (12, 15) and to use the demodulated signals (idemod) when determining the position of the sensor (20) in relation to the detection zone (18). <IMAGE>

IPC 1-7

G08B 13/24

IPC 8 full level

G01V 15/00 (2006.01); G08B 13/24 (2006.01)

CPC (source: EP)

G01V 15/00 (2013.01); G08B 13/2442 (2013.01); G08B 13/2445 (2013.01); G08B 13/2471 (2013.01); G08B 13/2485 (2013.01)

Citation (search report)

Designated contracting state (EPC)

DE ES FR GB IT NL

DOCDB simple family (publication)

WO 9729464 A1 19970814; CA 2245736 A1 19970814; CA 2245736 C 20030429; DE 69702652 D1 20000831; DE 69702652 T2 20010405; EP 0880763 A1 19981202; EP 0880763 B1 20000726; EP 0999531 A1 20000510; ES 2151717 T3 20010101; JP 2000510618 A 20000815; SE 506449 C2 19971215; SE 9601033 D0 19960319; SE 9601033 L 19970813; US 6137411 A 20001024

DOCDB simple family (application)

SE 9700199 W 19970211; CA 2245736 A 19970211; DE 69702652 T 19970211; EP 00100804 A 19970211; EP 97904707 A 19970211; ES 97904707 T 19970211; JP 52846097 A 19970211; SE 9601033 A 19960319; US 12513198 A 19981021